Sampling method and apparatus for consistency measurement

Abstract

A sampling device provides accurately repeatable samples for determination of consistency. A chamber is placed into the process line, and a piston in the chamber can be moved rearwardly to withdraw a quantity of process into the chamber. A sample container in communication with the chamber is also filled. The piston is moved forwardly to urge the process back into the process line, while the sample container remains full of process. The sample container has a known volume, and the piston in its forward position closes the sample container so the sample therein is limited to the known volume. The sample is transferred to a filter, and clean water assures that all solids are transferred to the filter.

What is claimed is:  
     
       1. Sampling apparatus, for use in taking a sample of process from a process line, said sampling apparatus comprising a chamber extending into said process line and in communication with said process line, piston means reciprocable within said chamber, a sample container contiguous with and in communication with said chamber, said sample container having a fixed volume, said piston means having a first position within said chamber and in said process line whereby said piston means blocks communication with said sample container and isolates said sample container from said process line, and a second position wherein said piston means is retracted to allow communication between said process line and said sample container through said chamber. 
     
     
       2. Sampling apparatus as claimed in  claim 1 , wherein said piston means, in said first position, closes said sample container so that said sample container comprises said fixed volume. 
     
     
       3. Sampling apparatus as claimed in  claim 2 , and further including water lines connected to said sample container for washing said sample from said sample container. 
     
     
       4. Sampling apparatus as claimed in  claim 1 , and further including means for selectively moving said piston from said first position to said second position and from said second position to said first position. 
     
     
       5. Sampling apparatus as claimed in  claim 1 , said chamber including a first end within said process line and a second end externally of said process line, said piston in said first position being substantially at said first end of said chamber for excluding process from said chamber. 
     
     
       6. Sampling apparatus as claimed in  claim 1 , and including filtering means for receiving a sample from said sample container. 
     
     
       7. Sampling apparatus as claimed in  claim 6 , and including valve means between said sample container and said filter means, said filter means comprising a drain for disposing of liquid, and a filter for retaining solids from said sample. 
     
     
       8. A method for sampling process for making consistency measurements, said method comprising the steps of inserting a chamber into the process line, said chamber having a sample container of known volume contiguous thereto and in communication therewith, moving a piston rearwardly in said chamber for providing communication between said process line and said sample container through said chamber for allowing said process to fill said sample container, moving said piston forwardly to close said sample container while retaining the process sample within said sample container. 
     
     
       9. A method as claimed in  claim 8 , and including the step of subsequently draining said sample container into a filtering means, and thereby collecting the solids in said process sample while allowing liquid to drain from the sample. 
     
     
       10. A method as claimed in  claim 9 , and further including the step of admitting clean water into said sample container for washing said process sample from said sample container, and collecting any solids with said filtering means. 
     
     
       11. A method as claimed in  claim 10 , wherein said steps of moving a piston rearwardly in said chamber and moving said piston forwardly in said chamber are repeated so that said filtering means collects solids from a plurality of process samples.